The present disclosure relates to a common mode filter and a method of manufacturing the same, and more particularly, to a common mode filter having improved impedance and a method of manufacturing the same.
In accordance with system configurations and increases in data capacity, high transmission rates have recently been required. A differential signal method is widely used as a fast transmission method.
Typically, when the frequency of a signal is converted to a high level in order to increase the transmission rate, unwanted electromagnetic waves, that is, noise, maybe generated by the signal having the high frequency, thereby causing a phenomenon in which the signal and noise overlap.
As a result, common mode noise occurs due to an imbalance between high speed differential signal lines, that is, two signal lines.
In order to remove common mode noise, a common mode filter is mainly used. Such a common mode filter is an electromagnetic interference (EMI) filter which is commonly used with high speed differential signal lines.
Common mode noise is generated by the differential signal line, and the common mode filter removes parts of noise that may not be removed by an existing electromagnetic interference filter. The common mode filter contributes to improving the electromagnetic compatibility (EMC) characteristics of home appliances, and the like or antenna characteristics of cellular phones, and the like.
However, when data is transmitted and received in a high frequency band, a GHz band, between a main device and a peripheral device in order to receive and transmit a large amount of data, a problem may occur in processing the data due to a delay of the signal and other interferences, as described above.
In particular, when various ports such as an image line, an acoustic signal line, and the like, are provided for use in a device such as a digital television (TV), problems such as delays in internal signal lines, transmission and reception distortion, and the like, as mentioned above, may more frequently occur.
An electromagnetic wave interference protection component, conventionally used to solve such problems, such as a common mode filter, has been manufactured as a wound type or a multilayer type common mode filter. In this regard, since such an electromagnetic wave interference protection component has a relatively large size and comparatively poor electrical properties, it may restrictively be applied to a circuit board having a relatively large area.
Furthermore, since many consumer electronic products are being made thinner, miniaturized, and given multiple functions while becoming ever more complex, electromagnetic wave interference protection components suitable for the above-mentioned conditions have been increasingly used. Wound-type or multilayer-type electromagnetic wave interference protection components for use in thinned and miniaturized electronic products have been manufactured, but since there are limitations in forming relatively complex internal circuits in a small area, the manufacturing of thin film-type common mode filter has recently been required.